| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20250827-i2c-pxa-fix-i2c-communication-v3-1-052c9b1966a2@gmail.com>
Date: Wed, 27 Aug 2025 19:13:58 +0200
From: Gabor Juhos <j4g8y7@...il.com>
To: Wolfram Sang <wsa@...nel.org>,
Wolfram Sang <wsa+renesas@...g-engineering.com>,
Andi Shyti <andi.shyti@...nel.org>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
Russell King <rmk+kernel@...linux.org.uk>, Andrew Lunn <andrew@...n.ch>,
Hanna Hawa <hhhawa@...zon.com>
Cc: Robert Marko <robert.marko@...tura.hr>,
Linus Walleij <linus.walleij@...aro.org>,
Russell King <rmk+kernel@...linux.org.uk>, linux-i2c@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
Gabor Juhos <j4g8y7@...il.com>, stable@...r.kernel.org
Subject: [PATCH v3 1/2] i2c: pxa: defer reset on Armada 3700 when recovery
is used
The I2C communication is completely broken on the Armada 3700 platform
since commit 0b01392c18b9 ("i2c: pxa: move to generic GPIO recovery").
For example, on the Methode uDPU board, probing of the two onboard
temperature sensors fails ...
[ 7.271713] i2c i2c-0: using pinctrl states for GPIO recovery
[ 7.277503] i2c i2c-0: PXA I2C adapter
[ 7.282199] i2c i2c-1: using pinctrl states for GPIO recovery
[ 7.288241] i2c i2c-1: PXA I2C adapter
[ 7.292947] sfp sfp-eth1: Host maximum power 3.0W
[ 7.299614] sfp sfp-eth0: Host maximum power 3.0W
[ 7.308178] lm75 1-0048: supply vs not found, using dummy regulator
[ 32.489631] lm75 1-0048: probe with driver lm75 failed with error -121
[ 32.496833] lm75 1-0049: supply vs not found, using dummy regulator
[ 82.890614] lm75 1-0049: probe with driver lm75 failed with error -121
... and accessing the plugged-in SFP modules also does not work:
[ 511.298537] sfp sfp-eth1: please wait, module slow to respond
[ 536.488530] sfp sfp-eth0: please wait, module slow to respond
...
[ 1065.688536] sfp sfp-eth1: failed to read EEPROM: -EREMOTEIO
[ 1090.888532] sfp sfp-eth0: failed to read EEPROM: -EREMOTEIO
After a discussion [1], there was an attempt to fix the problem by
reverting the offending change by commit 7b211c767121 ("Revert "i2c:
pxa: move to generic GPIO recovery""), but that only helped to fix
the issue in the 6.1.y stable tree. The reason behind the partial succes
is that there was another change in commit 20cb3fce4d60 ("i2c: Set i2c
pinctrl recovery info from it's device pinctrl") in the 6.3-rc1 cycle
which broke things further.
The cause of the problem is the same in case of both offending commits
mentioned above. Namely, the I2C core code changes the pinctrl state to
GPIO while running the recovery initialization code. Although the PXA
specific initialization also does this, but the key difference is that
it happens before the controller is getting enabled in i2c_pxa_reset(),
whereas in the case of the generic initialization it happens after that.
Change the code to reset the controller only before the first transfer
instead of before registering the controller. This ensures that the
controller is not enabled at the time when the generic recovery code
performs the pinctrl state changes, thus avoids the problem described
above.
As the result this change restores the original behaviour, which in
turn makes the I2C communication to work again as it can be seen from
the following log:
[ 7.363250] i2c i2c-0: using pinctrl states for GPIO recovery
[ 7.369041] i2c i2c-0: PXA I2C adapter
[ 7.373673] i2c i2c-1: using pinctrl states for GPIO recovery
[ 7.379742] i2c i2c-1: PXA I2C adapter
[ 7.384506] sfp sfp-eth1: Host maximum power 3.0W
[ 7.393013] sfp sfp-eth0: Host maximum power 3.0W
[ 7.399266] lm75 1-0048: supply vs not found, using dummy regulator
[ 7.407257] hwmon hwmon0: temp1_input not attached to any thermal zone
[ 7.413863] lm75 1-0048: hwmon0: sensor 'tmp75c'
[ 7.418746] lm75 1-0049: supply vs not found, using dummy regulator
[ 7.426371] hwmon hwmon1: temp1_input not attached to any thermal zone
[ 7.432972] lm75 1-0049: hwmon1: sensor 'tmp75c'
[ 7.755092] sfp sfp-eth1: module MENTECHOPTO POS22-LDCC-KR rev 1.0 sn MNC208U90009 dc 200828
[ 7.764997] mvneta d0040000.ethernet eth1: unsupported SFP module: no common interface modes
[ 7.785362] sfp sfp-eth0: module Mikrotik S-RJ01 rev 1.0 sn 61B103C55C58 dc 201022
[ 7.803426] hwmon hwmon2: temp1_input not attached to any thermal zone
Link: https://lore.kernel.org/r/20230926160255.330417-1-robert.marko@sartura.hr #1
Cc: stable@...r.kernel.org # 6.3+
Fixes: 20cb3fce4d60 ("i2c: Set i2c pinctrl recovery info from it's device pinctrl")
Signed-off-by: Gabor Juhos <j4g8y7@...il.com>
---
Changes in v3:
- rebase on tip of i2c/for-current
- rework the patch and use a different approach which does not requires
modification in the I2C core code and update commit description
acccordingly
- remove Imre's SoB tag, it should have been a Reviewed-by tag, but due
to the rework this is an entirely different patch so that does not
apply anyway
- use Link tag for the URL of the referenced LKML thread
- Link to v2: https://lore.kernel.org/r/20250811-i2c-pxa-fix-i2c-communication-v2-2-ca42ea818dc9@gmail.com
Changes in v2:
- rebase and retest on tip of i2c/for-current
- Link to v1: https://lore.kernel.org/r/20250511-i2c-pxa-fix-i2c-communication-v1-2-e9097d09a015@gmail.com
---
drivers/i2c/busses/i2c-pxa.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 968a8b8794dac3398a68d827c567aa5bb73ae3d7..70acf33e1d573231f84a1f09cffb376a8277351d 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -268,6 +268,7 @@ struct pxa_i2c {
struct pinctrl *pinctrl;
struct pinctrl_state *pinctrl_default;
struct pinctrl_state *pinctrl_recovery;
+ bool reset_before_xfer;
};
#define _IBMR(i2c) ((i2c)->reg_ibmr)
@@ -1144,6 +1145,11 @@ static int i2c_pxa_xfer(struct i2c_adapter *adap,
{
struct pxa_i2c *i2c = adap->algo_data;
+ if (i2c->reset_before_xfer) {
+ i2c_pxa_reset(i2c);
+ i2c->reset_before_xfer = false;
+ }
+
return i2c_pxa_internal_xfer(i2c, msgs, num, i2c_pxa_do_xfer);
}
@@ -1521,7 +1527,16 @@ static int i2c_pxa_probe(struct platform_device *dev)
}
}
- i2c_pxa_reset(i2c);
+ /*
+ * Skip reset on Armada 3700 when recovery is used to avoid
+ * controller hang due to the pinctrl state changes done by
+ * the generic recovery initialization code. The reset will
+ * be performed later, prior to the first transfer.
+ */
+ if (i2c_type == REGS_A3700 && i2c->adap.bus_recovery_info)
+ i2c->reset_before_xfer = true;
+ else
+ i2c_pxa_reset(i2c);
ret = i2c_add_numbered_adapter(&i2c->adap);
if (ret < 0)
--
2.50.1
Powered by blists - more mailing lists